/*
** $Id: ldump.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $
** save precompiled Lua chunks
** See Copyright Notice in lua.h
*/

#include <stddef.h>
#include <string.h>

#define ldump_c
#define LUA_CORE

#include "lua.h"

#include "lobject.h"
#include "lstate.h"
#include "lundump.h"

typedef struct
{
    lua_State *L;
    lua_Writer writer;
    void *data;
    int strip;
    int status;
    DumpTargetInfo target;
    size_t wrote;
} DumpState;

#define DumpMem(b,n,size,D) DumpBlock(b,(n)*(size),D)
#define DumpVar(x,D)        DumpMem(&x,1,sizeof(x),D)

static void DumpBlock(const void *b, size_t size, DumpState *D)
{
    if (D->status == 0)
    {
        lua_unlock(D->L);
        D->status = (*D->writer)(D->L, b, size, D->data);
        D->wrote += size;
        lua_lock(D->L);
    }
}

static void DumpChar(int y, DumpState *D)
{
    char x = (char)y;
    DumpVar(x, D);
}

static void Align4(DumpState *D)
{
    while (D->wrote & 3)
        DumpChar(0, D);
}

static void MaybeByteSwap(char *number, size_t numbersize, DumpState *D)
{
    int x = 1;
    int platform_little_endian = *(char *)&x;
    if (platform_little_endian != D->target.little_endian)
    {
        unsigned long i;
        for (i = 0; i < numbersize / 2; i++)
        {
            char temp = number[i];
            number[i] = number[numbersize - 1 - i];
            number[numbersize - 1 - i] = temp;
        }
    }
}

static void DumpIntWithSize(int x, int sizeof_int, DumpState *D)
{
    /* dump signed integer */
    switch (sizeof_int)
    {
    case 1:
    {
        if (x > 0x7F || x < (-0x80)) D->status = LUA_ERR_CC_INTOVERFLOW;
        DumpChar(x, D);
    }
    break;
    case 2:
    {
        if (x > 0x7FFF || x < (-0x8000)) D->status = LUA_ERR_CC_INTOVERFLOW;
        int16_t y = (int16_t)x;
        MaybeByteSwap((char *)&y, 2, D);
        DumpVar(y, D);
    }
    break;
    case 4:
    {
        /* Need to reduce bounds by 1 to avoid messing 32-bit compilers up */
        if (x > 0x7FFFFFFE || x < (-0x7FFFFFFF)) D->status = LUA_ERR_CC_INTOVERFLOW;
        int32_t y = (int32_t)x;
        MaybeByteSwap((char *)&y, 4, D);
        DumpVar(y, D);
    }
    break;
    default:
        lua_assert(0);
    }
}

static void DumpInt(int x, DumpState *D)
{
    DumpIntWithSize(x, D->target.sizeof_int, D);
}

static void DumpSize(uint32_t x, DumpState *D)
{
    /* dump unsigned integer */
    switch (D->target.sizeof_strsize_t)
    {
    case 1:
    {
        if (x > 0xFF) D->status = LUA_ERR_CC_INTOVERFLOW;
        DumpChar(x, D);
    }
    break;
    case 2:
    {
        if (x > 0xFFFF) D->status = LUA_ERR_CC_INTOVERFLOW;
        uint16_t y = (uint16_t)x;
        MaybeByteSwap((char *)&y, 2, D);
        DumpVar(y, D);
    }
    break;
    case 4:
    {
        /* Reduce bounds to avoid messing 32-bit compilers up */
        if (x > 0xFFFFFFFE) D->status = LUA_ERR_CC_INTOVERFLOW;
        uint32_t y = x;
        MaybeByteSwap((char *)&y, 4, D);
        DumpVar(y, D);
    }
    break;
    default:
        lua_assert(0);
    }
}

static void DumpNumber(lua_Number x, DumpState *D)
{
#if defined( LUA_NUMBER_INTEGRAL ) && !defined( LUA_CROSS_COMPILER )
    DumpIntWithSize(x, D->target.sizeof_lua_Number, D);
#else // #if defined( LUA_NUMBER_INTEGRAL ) && !defined( LUA_CROSS_COMPILER )
    if (D->target.lua_Number_integral)
    {
        if (((float)(int)x) != x) D->status = LUA_ERR_CC_NOTINTEGER;
        DumpIntWithSize(x, D->target.sizeof_lua_Number, D);
    }
    else
    {
        switch (D->target.sizeof_lua_Number)
        {
            /* do we need bounds checking? */
        case 4:
        {
            float y = x;
            MaybeByteSwap((char *)&y, 4, D);
            DumpVar(y, D);
        }
        break;
        case 8:
        {
            double y = x;
            // ARM FPA mode: keep endianness, but swap high and low parts of the
            // memory representation. This is the default compilation mode for ARM
            // targets with non-EABI gcc
            if (D->target.is_arm_fpa)
            {
                char *pnum = (char *)&y, temp[4];
                memcpy(temp, pnum, 4);
                memcpy(pnum, pnum + 4, 4);
                memcpy(pnum + 4, temp, 4);
            }
            MaybeByteSwap((char *)&y, 8, D);
            DumpVar(y, D);
        }
        break;
        default:
            lua_assert(0);
        }
    }
#endif // #if defined( LUA_NUMBER_INTEGRAL ) && !defined( LUA_CROSS_COMPILER )
}

static void DumpCode(const Proto *f, DumpState *D)
{
    DumpInt(f->sizecode, D);
    char buf[10];
    int i;
    Align4(D);
    for (i = 0; i < f->sizecode; i++)
    {
        memcpy(buf, &f->code[i], sizeof(Instruction));
        MaybeByteSwap(buf, sizeof(Instruction), D);
        DumpBlock(buf, sizeof(Instruction), D);
    }
}

static void DumpString(const TString *s, DumpState *D)
{
    if (s == NULL || getstr(s) == NULL)
    {
        strsize_t size = 0;
        DumpSize(size, D);
    }
    else
    {
        strsize_t size = (strsize_t)s->tsv.len + 1;    /* include trailing '\0' */
        DumpSize(size, D);
        DumpBlock(getstr(s), size, D);
    }
}

static void DumpFunction(const Proto *f, const TString *p, DumpState *D);

static void DumpConstants(const Proto *f, DumpState *D)
{
    int i, n = f->sizek;
    DumpInt(n, D);
    for (i = 0; i < n; i++)
    {
        const TValue *o = &f->k[i];
        DumpChar(ttype(o), D);
        switch (ttype(o))
        {
        case LUA_TNIL:
            break;
        case LUA_TBOOLEAN:
            DumpChar(bvalue(o), D);
            break;
        case LUA_TNUMBER:
            DumpNumber(nvalue(o), D);
            break;
        case LUA_TSTRING:
            DumpString(rawtsvalue(o), D);
            break;
        default:
            lua_assert(0);          /* cannot happen */
            break;
        }
    }
    n = f->sizep;
    DumpInt(n, D);
    for (i = 0; i < n; i++) DumpFunction(f->p[i], f->source, D);
}

static void DumpDebug(const Proto *f, DumpState *D)
{
    int i, n;
    n = (D->strip) ? 0 : f->sizelineinfo;
    DumpInt(n, D);
    Align4(D);
    for (i = 0; i < n; i++)
    {
        DumpInt(f->lineinfo[i], D);
    }

    n = (D->strip) ? 0 : f->sizelocvars;
    DumpInt(n, D);
    for (i = 0; i < n; i++)
    {
        DumpString(f->locvars[i].varname, D);
        DumpInt(f->locvars[i].startpc, D);
        DumpInt(f->locvars[i].endpc, D);
    }

    n = (D->strip) ? 0 : f->sizeupvalues;
    DumpInt(n, D);
    for (i = 0; i < n; i++) DumpString(f->upvalues[i], D);
}

static void DumpFunction(const Proto *f, const TString *p, DumpState *D)
{
    DumpString((f->source == p || D->strip) ? NULL : f->source, D);
    DumpInt(f->linedefined, D);
    DumpInt(f->lastlinedefined, D);
    DumpChar(f->nups, D);
    DumpChar(f->numparams, D);
    DumpChar(f->is_vararg, D);
    DumpChar(f->maxstacksize, D);
    DumpCode(f, D);
    DumpConstants(f, D);
    DumpDebug(f, D);
}

static void DumpHeader(DumpState *D)
{
    char buf[LUAC_HEADERSIZE];
    char *h = buf;

    /* This code must be kept in sync wiht luaU_header */
    memcpy(h, LUA_SIGNATURE, sizeof(LUA_SIGNATURE) - 1);
    h += sizeof(LUA_SIGNATURE) - 1;
    *h++ = (char)LUAC_VERSION;
    *h++ = (char)LUAC_FORMAT;
    *h++ = (char)D->target.little_endian;
    *h++ = (char)D->target.sizeof_int;
    *h++ = (char)D->target.sizeof_strsize_t;
    *h++ = (char)sizeof(Instruction);
    *h++ = (char)D->target.sizeof_lua_Number;
    *h++ = (char)D->target.lua_Number_integral;

    DumpBlock(buf, LUAC_HEADERSIZE, D);
}

/*
** dump Lua function as precompiled chunk with specified target
*/
int luaU_dump_crosscompile(lua_State *L, const Proto *f, lua_Writer w, void *data, int strip, DumpTargetInfo target)
{
    DumpState D;
    D.L = L;
    D.writer = w;
    D.data = data;
    D.strip = strip;
    D.status = 0;
    D.target = target;
    D.wrote = 0;
    DumpHeader(&D);
    DumpFunction(f, NULL, &D);
    return D.status;
}

/*
 ** dump Lua function as precompiled chunk with local machine as target
 */
int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data, int strip)
{
    DumpTargetInfo target;
    int test = 1;
    target.little_endian = *(char *)&test;
    target.sizeof_int = sizeof(int);
    target.sizeof_strsize_t = sizeof(strsize_t);
    target.sizeof_lua_Number = sizeof(lua_Number);
    target.lua_Number_integral = (((lua_Number)0.5) == 0);
    target.is_arm_fpa = 0;
    return luaU_dump_crosscompile(L, f, w, data, strip, target);
}
